Questions regarding password-based authentication and password management

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4
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2answers
1k views

Sudo Su automated login

I want to automate the login process with sudo su. I have seen lot of questions on these, but none of them are working for me. Automate login with sudo and su Here's my what I tried so far echo ...
4
votes
3answers
2k views

chroot permission denied! But Im root!

I am trying to chroot into an old HD to change a forgotten password, but chroot says permission denied? what gives? I am root! The harddrive I am trying to chroot into is an old version of edUbuntu ...
4
votes
3answers
2k views

SCP command with selected file and directories for download ask's for password for each new file or directory

On my Fedora 20 system I use scp a lot, and this is the second time I encounter this, when I run this command: scp -r -P PORT user@host:/home/user/something/{file1,folder1,folder2,folder3,folder4} ...
4
votes
3answers
664 views

Securely feeding a program with a password

After understanding the problem with using a password in the command line, I need to find a way of feeding a program with a password without it being a problem (without the password being recorded ...
4
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3answers
248 views

Automatic login via ssh (no GUI environment installed / no ssh-agent available)?

I have three systems, and I want to have them doing backups between them periodically. The two of them, have Debian Wheezy installed and the other one has Ubuntu 12.04 installed. Only the Ubuntu has a ...
4
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3answers
764 views

How to unlock account for public key ssh authorization, but not for password authorization?

The ssh won't let me login, because account is locked. I want to unlock the user on my server for public key authorization over ssh, but do not enable password-ed login. I've tried: # passwd -u ...
4
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2answers
2k views

/etc/shadow date of last password change—UTC or local time?

man 5 shadow gives the following description of the third field in each line: The date of the last password change, expressed as the number of days since Jan 1, 1970. The value 0 has a ...
4
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2answers
69 views

Trying to crack a weak password using John

I have a computer from the 1990s. It has an (extent) EFS file-system which cannot be wrote to in linux, so i cannot reset the password manually. So i have to crack my password. For this I am trying to ...
4
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2answers
217 views

Why rejection of password is much slower than acceptance of it? [duplicate]

In both my Linux and OSX machines when I type in the password to login, a correct password is accepted immediately. However, if I type a wrong password, checking process takes much longer. How is ...
4
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3answers
14k views

Lost password for a user on a Linux Server: How reset it?

On a Server an user 16040 has lost his password. I have password for root but don't have password for user 16040. How can I reset his password? With passwd 16040, unix ask me current password that I ...
4
votes
1answer
2k views

How to reset password on an encrypted fs?

I've got a laptop which I haven't used since the last summer vacation: I did put Debian 7 on it and used Debian's feature to fully encrypt the disk, besides a tiny bootloader (or a tiny partition) I ...
4
votes
4answers
344 views

Login into a GNU/Linux distribution is taking too long

So, When I try to login with my username and password (in tty), and insert a wrong password, I need to wait around 5 seconds for the system to tell me that the password is wrong. Why the validating ...
4
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3answers
441 views

Something like pwgen-win for linux?

Is there some kind of pwd generator for Linux that has a nice GUI and options like this one for Windows? I know that there is pwgen, but as far as I know it does not support mouse/keyboard entropy and ...
4
votes
2answers
218 views

Determining the Password Status of a User

I have a debian box that I connect to via SSH. I have removed the password from the users root, and my personal account using the instructions here, and set up a public/private key pair so I can log ...
4
votes
1answer
475 views

Encrypt word X to /etc/shadow encryption

I've changed my password to X and the shadow file has changed to: ahmad:$1$oYINSKjP$eCkCtJV/2dXerAD57WQPj/:15425:0:99999:7::: I see the encrypted X as $1$oYINSKjP$eCkCtJV/2dXerAD57WQPj/. How can I ...
4
votes
2answers
330 views

Why should you NEVER edit the /etc/shadow file directly?

In another answer here on UNIX & Linux Stack Exchange Michael D Parker wrote, in response to someone saying that doing so was "safe", that:Usually you should NEVER edit the /etc/shadow file ...
4
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2answers
255 views

User created without a password behaves as if he had one

Inside one of my scripts, I created an user based on a directory arrangement on another machine. The thing is that this user, created without a password, behaves just as he had one : he has sudo ...
4
votes
1answer
15k views

How to set password for users in AIX using single line command?

Is there any way in which I can set the password for a newly created user account in AIX in a one line command? I don't want to give any prompt to the user. If there is a command, it should set the ...
4
votes
2answers
400 views

Password protecting a system file? (e.g. /etc/resolv.conf)

I am trying to parental control myself by restricting web access via OpenDNS. The OpenDNS account password will be handed to someone trustworthy. Now, I want to put some restriction on the ...
4
votes
1answer
15k views

How to create a user with given password on SuSE from command line?

I need to create bunch of new users with given password. What I want is a script that I would pass the user name of new user and it will create/add the user and set its password. (the password is the ...
4
votes
3answers
2k views

scp: localhost password not accepted

I'm attempting to copy a public key to a remote server. I'm logged in locally as [localname] and the key resides locally at ~/.ssh/. I'm also ssh'd into [remote.com] as [remotename], and attempting to ...
4
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2answers
609 views

Is it possible (and a good idea) to do `pw lock root` on FreeBSD?

I have set up sudo on my FreeBSD server. As I now never want to log in as root anymore, I was wondering whether I should do sudo pw lock root. My questions are: Is this possible, without forever ...
4
votes
1answer
569 views

What triggers this screen prompt “Screen used by <username> on host01.”?

Every now and then some key combination clears my working (Gnu) screen and brings up this message: Screen used by <username> on host01 Password: What key combination causes this and what does ...
4
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2answers
2k views

How could I eliminate Kerberos for passwd?

When I issue a command to change my password like this: sudo passwd huahsin The system prompt me: Current Kerberos password: I don't know what I have done to the system configuration, how could I ...
4
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2answers
9k views

Avoid “Authentication token manipulation error” on password change

I'm implementing a security policy that will force the users to introduce stricter passwords when they change their own: The /etc/pam.d/passwd configuration file is: #%PAM-1.0 auth include ...
4
votes
1answer
31k views

How to lock users after 5 unsuccessful login tries?

How to lock users after 5 unsuccessful login tries? I gathered a few distributions/versions to how to do it, but I can't test it. RHEL4: by adding the: auth required ...
4
votes
1answer
399 views

How to change the forgotten root password?

I am very new to Debian linux, I forgot my root password...actually I think I know what it is because it is the same password I have for pretty much everything but in the Terminal in tell me "Sorry, ...
4
votes
3answers
276 views

Randomise or shred memory of an application

Is it possible to randomise or shred memory of a particular application just after its life ends, or better, whenever it deallocates some memory? A command-line utility like this would be perfect: ...
4
votes
1answer
53 views

Is it possible to add a password to moving or copying specific files on Linux?

I have a directory setup very nicely(i.e organized with READMEs and easy navigation etc.). I would like people to be able to access the files in this directory maybe even copy them to their own ...
4
votes
1answer
104 views

Change the root password of a Linux image

I'm building a jessie build of Debian. Passwords are saved in /etc/shadow in the build tree, but they are salted obviously so I cannot change it just by editing the file. If this was my installed ...
4
votes
1answer
103 views

Self-contained password manager with CLI [closed]

I'm looking for a password manager that has the following properties: The manager is entirely self-contained. I take and install a directory on a thumbdrive and execute from that drive. It should ...
4
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1answer
2k views

Can pwgen output passwords of a certain length?

I'm using the command line tool pwgen to generate passwords because I love the repeatability you get with the sha1 command line flag. To quote the man page: -H, --sha1=/path/to/file[#seed] ...
4
votes
1answer
3k views

Debian Log In Failure With Correct Password

So I have a Debian distro at home (considering getting ubuntu), and I can't login. When I use the correct password is does this thing where it makes it look like it's going to login, and then it ...
4
votes
1answer
1k views

Why ssh-copy-id prompts for the local user password three times?

Noticed from my previous question that when trying to copy an SSH public key to a remote host via ssh-copy-id, I am prompted for the local user password three times: ssh-copy-id myuser@myserver ...
4
votes
2answers
2k views

Two-step remote ssh without password

I'm looking to ssh from my localhost to a remote server, and from there to a remote computer. I currently have it set up so that the remote computer and remote server have passwordless ssh-ing set up ...
4
votes
2answers
123 views

how to prevent a buffer from swap

this question is specific to Unix and Linux. but it is programming and security, too. my program will get a clear password or decryption key by one of a few ways (decrypting a password file, asking ...
4
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2answers
119 views

SSH password requested when in Tmux

When I connect to my remote machine I do authenticate using a rsa key (I think is rsa, don't remember). If I do ssh from a regular shell I get logged on the machine without a password. However if I ...
4
votes
2answers
13k views

Change Password of a user in /etc/shadow

I would like to change the password of a user in the /etc/shadow. I can't use password changing programs like passwd. It must be done by editing the /etc/shadow. The /etc/shadow is on a mounted hard ...
4
votes
1answer
282 views

Can linux use a mix of SHA-1 and CRYPT passwords?

We have an automated sync-routine that uses useradd to create new users on a Ubuntu 10.04 machine. The application launching the routine provided both username and CRYPT-encrypted password. However, ...
4
votes
1answer
84 views

password store storing some passwords in plain text

I red about the password management program pass in a question on this forum and decided to try it. I installed from the download page (tarball 1.6.3). I created some test entries and then some real ...
4
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2answers
163 views

Using $ in a password

Lets assume that password of my server is Abcd$1234 I am trying to ftp a file from other server to my server using the following in shell script ftp -inv (IP) << EOF user Username Abcd$1234 ...
4
votes
2answers
10k views

Deleting a samba user: pbdedit vs. smbpasswd, what's the difference?

What is the difference between $ pdbedit -x and $ smbpasswd -x to delete samba users?
4
votes
1answer
159 views

Where are passwords stored and how are they encrypted in OS X?

I know that on a Linux system passwords are stored in /etc/shadow and are salted and encrypted using a one way hashing algorithm like MD5, SHA-256 or SHA-512. It looks like there is no /etc/shadow ...
4
votes
1answer
1k views

Validate AIX Password for root from script

Looking for a way in a shell script to validate the password for for root on an (AIX) matches a standardized plain text password. This query is similar to another one on this site. I have access to ...
4
votes
1answer
2k views

Password expiry in Samba v3.0

I'm trying to setup a Samba server which asks new users to change their password on their first login and makes passwords expire after 90 days. I was able to setup the 90 days expiry date but the ...
4
votes
1answer
440 views

how to verify if root password changed correctly

I have an OpsWare task, that changes root passwords on a massive number of servers, by replacing the root's password hash in /etc/shadow file. I need a script of some sort, which preferably runs ...
3
votes
4answers
6k views

What command should I run after making changes to /etc/passwd file

I have made some changes to /etc/passwd file ,now I wanted to see if the effect of changes taken place or not .What command should I run for that. For example after making change to ...
3
votes
5answers
2k views

Encrypt a password the same way mysql does

I've created a user ... but forgotten the password mysql> create user 'blayo'@'%' identified by 'right'; Which Linux command line tool can encrypt the password the same way mysql 5.5 does ? ...
3
votes
3answers
258 views

How to mask passwords in 'watch' command?

I am using watch to monitor the progress of a MySQL replication slave. The way I have it set up now, the password shows up in the header of the watch output. I am not exceedingly worried that someone ...
3
votes
2answers
3k views

Second field in /etc/shadow

If the second field of the /etc/shadow file is set to !!, does it mean that the account is disabled? Or does it mean that the account is active with no password assigned?